1. Field of the Invention
The present invention relates to a socket assembly, and more particularly to a zero insertion force (ZIF) socket assembly having a pick-up cap with a lock-up preventing a cam thereof from rotating during transportation.
2. Description of the Prior Art
A zero insertion force (ZIF) socket usually has a cam to drive a cover along a base such that a plurality of pins of an electronic package carried by the cover will contact with a plurality of contacts of the base of the ZIF socket. The use of the cam mechanism benefits a low-profile and weight of the socket. U.S. Pat. No. 6,609,926 issued to Chen et al. on Aug. 26, 2003, discloses a ZIF socket comprising a base with a plurality of contacts thereof and a cover with a plurality of through holes mounted to the base. A cam with a plurality of off-center-arranged shafts disposed between the base and the cover, for driving the cover to move along the base in a horizontal direction. The cam is rotated in a substantially 180 degrees such that a cam-shaft is to drive the cover to move between an opened position and a closed position. When the cover is located in the opened position, the electronic package can be readily mounted on the cover with pins extending through the cover and reach into passageways of the base; then the cam is rotated from one position to the other position to drive the cover to move to the closed position, making those inserted pins to engage with the contacts received in the passageways of the base. By this arrangement, the ZIF socket and the electronic package are established a reliable electrical connection therebetween. In addition, the ZIF socket further comprises a pick-up cap mounted upon the cover and picked up by a vacuum nozzle for placing the ZIF socket onto a printed circuit board.
Ideally, when the pin legs are inserted into the passageway through the through hole of cover which is positioned at the opened position, there should not have any contact between the pin leg and contact engaging arms disposed within the passageway. However, if the cover is moved and away from its opened position, the through hole of the cover may accidentally in align with the contact engaging arms. In this case, the insertion of the pin legs of the IC package will adversely damage the contact engaging arms.
Therefore, it is need to find a new ZIF socket to overcome the problems mentioned above.